# Why

closes expo#38223

The above issue didn't include full repro steps so here they are:

### Prerequisites

- An Expo app with `expo-notifications` and `expo-task-manager`
configured
- A registered `BACKGROUND_NOTIFICATION_TASK` via
`TaskManager.defineTask` and `Notifications.registerTaskAsync`

### Sending push notifications

Install `expo-server-sdk`:

```bash
mkdir /tmp/expo-push-test && cd /tmp/expo-push-test
npm init -y && npm install expo-server-sdk
```

Create `send.mjs`:

```js
import { Expo } from "expo-server-sdk";

const expo = new Expo();
const token = "ExponentPushToken[YOUR_TOKEN_HERE]";
const mode = process.argv[2] // data (headless) or regular notification

const message = mode === "data"
  ? { to: token, data: { type: "background_task", timestamp: String(Date.now()) }, _contentAvailable: true }
  : { to: token, title: "Test", body: `Notification at ${new Date().toLocaleTimeString()}` };

const [chunk] = expo.chunkPushNotifications([message]);
console.log(`Sending ${mode} notification...`);
const result = await expo.sendPushNotificationsAsync(chunk);
console.log("Result:", JSON.stringify(result, null, 2));
```

### Reproduction steps

1. **Launch the app** and confirm it's in the foreground
2. **Send a display notification:**
3. **Kill the app** (swipe away from recents)
4. **Tap the notification** from the system tray — the app opens
5. **Wait for the app to fully load**
6. **Send a data-only notification:**

### Expected behavior

The `BACKGROUND_NOTIFICATION_TASK` executes and JS receives the
notification.

### Actual behavior (before fix)

The background task silently fails. All subsequent data-only
notifications also fail — the task never runs again until the app is
force-stopped and restarted.

### Root cause

When tapping the notification in step 4, `handleNotificationResponse`
called `runTaskManagerTasks` while the app was still launching. This
started a headless React instance that raced with the foreground app.
The foreground `TaskManager` got misclassified as headless (via
`isStartedByHeadlessLoader`), then wiped by `invalidateAppRecord` —
permanently breaking background task execution for the session.

# How

Only call `runTaskManagerTasks` for non-default notification actions
(custom action buttons like "Mark as read").

The default tap (`DEFAULT_ACTION_IDENTIFIER`) always opens the app, so
there's no need for headless task execution — the foreground app handles
the response via listeners.



The fix is in `if (!isAppInForeground() &&
notificationResponse.actionIdentifier !=
NotificationResponse.DEFAULT_ACTION_IDENTIFIER)` but I also resolved one
older TODO around an awkward use of `WeakHashMap`.

# Test Plan

- tested on device using the repro steps

# Checklist

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- [x] I added a `changelog.md` entry and rebuilt the package sources
according to [this short
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- [ ] This diff will work correctly for `npx expo prebuild` & EAS Build
(eg: updated a module plugin).
- [ ] Conforms with the [Documentation Writing Style
Guide](https://github.com/expo/expo/blob/main/guides/Expo%20Documentation%20Writing%20Style%20Guide.md)